So just an update here, but I tried the "Wallbridge" method of bolt manipulation, and I'm happy to report that this method can still be effectively employed using this tac knob. By securing the recessed section of the knob between my thumb and index finger, the middle finger was still able to fall nicely into place and actuate the trigger. I was able to effectively engage the trigger in rapid succession while cycling the bolt. Keep in mind that while this works with this particular tac knob for this specific application, your results may very depending on the aftermarket tac knob you might be considering.
ETA: As stated previously, I couldn't get used to shooting the "Wallbridge" method using the standard unmolested bolt knob. Strangely enough however, I'm finding myself liking it now that I've been playing around with it using this tac knob. I suspect that it is in part due to the recess in the knob, which allows for spot to place your thumb and index finger in a way that feels natural. Also, the knob extends a bit further out, so the middle finger drops right into the trigger well without having to stretch it out. I found that by keeping my middle finger slightly curved, it just falls right into place and everything feels quite natural in that regard. I'll do some extensive shooting using this method before I come to a conclusive decision as to whether or not I'll adopt this as a standard shooting technique for the GSR.